The results showed that the applied PGRs had significant positive effects on plant height, leaf area index, higher number of flowers reduced the abscission and increased t[r]
Trang 1Original Research Article https://doi.org/10.20546/ijcmas.2017.611.115
Effect of Various Plant Growth Regulators on Growth and
Yield of Cotton (Gossypium hirsutum)
S.S Sabale, G.R Lahane* and S.J Dhakulkar
Department of Genetics and Plant breeding, C P College of Agriculture,
S D Agriculture University, Sardarkrushinagar-385506, Gujarat, India
*Corresponding author
A B S T R A C T
Introduction
Cotton is a sub-tropical, perennial plant with
indeterminate growth habit Vegetative and
reproductive growth occurs simultaneously
where vegetative growth is necessary to
support reproductive growth The growth
habits of these varieties/hybrids combined
with high availability of nutrients, timely
rainfall or irrigation and delayed fruit
retention can encourage excessive vegetative
growth Excessive vegetative growth leads to
severe production problems like fruit
abortion, delayed maturity, boll rot and
harvest difficulties The physiological
efficiency of a plant can be improved by prolonging photosynthesis, reducing photorespiration, better partitioning of photo assimilates, improving mineral ions uptake and stimulating nitrogen metabolism All these processes are inter-linked through several interactions and influence growth and productivity
Plant growth regulators have been found to influence these processes in one way or the other Plant growth regulators are substances when added in small amounts modify the
ISSN: 2319-7706 Volume 6 Number 11 (2017) pp 978-989
Journal homepage: http://www.ijcmas.com
Plant growth regulators (PGR) are used in cotton (Gossypium hirsutum L.) production to
balance vegetative and reproductive growth, as well as to increase seed cotton yield and lint quality Field experiments were conducted with some PGRs to determine their effects
on yield and yield components of cotton using cv Bt Cotton and local hybrid The field
experiment was conducted during Kharif season of 2012-13 at the Agronomy Instructional
Farm, Chimanbhai Patel College of Agriculture, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, and District: Banaskantha (North Gujarat) The experiment was laid in factorial randomized block design with three replications Eighteen treatment combinations comprised of the foliar spray of growth regulators and nutrients viz 30 ppm NAA, 50 ppm GA3, 200 ppm Mepiquat chloride, 2 % Urea and control were applied at 60 and 80 days after sowing The results showed that the applied PGRs had significant positive effects on plant height, leaf area index, higher number of flowers reduced the abscission and increased the flower retention percentage, which in turn helped in getting higher seed cotton yield The RGR and NAR decreased continuously in all the treatments
K e y w o r d s
PGRs, Cotton,
Gossypium hirsutum
L., Yield
Accepted:
10 September 2017
Available Online:
10 November 2017
Article Info
Trang 2growth of plant usually by stimulating or
inhibiting part of the natural growth
regulation They are considered as new
generation of agrochemicals after fertilizers,
pesticides and herbicides Plant growth
regulators are capable of increasing yield by
100-200 per cent under laboratory conditions,
10 - 15 per cent in the field conditions (Kiran
Kumar, 2001)
Plant growth regulators like promoters,
inhibitors or retardants play a key role in
internal control mechanism of plant growth
by interacting with key metabolic processes
such as nucleic acid and protein synthesis
The most commonly used growth regulator in
cotton is mepiquatchloride, which is an
inhibitor of gibberellic acid This curtails
excessive vegetative growth and increases the
yield
Generally sowing of cotton in Gujarat is done
at the end of May to first week of June, so
there will be maximum number of bolls per
plant at the end of August to first fortnight of
September From last few years weather
pattern has changed and rainfall withdraw at
the end of August So cotton faces moisture
stress at this period on contrast to this plant of
cotton at that time requires maximum water
and foods for the development of bolls The
drought at this time create internal hormones
imbalance i.e production of abscisic acid and
ethylene inhibits the production of Auxins,
Gibberellins and Cytokinins which results
into abscission of leaves and squares and in
severe condition also abscission of bolls and
ultimately parawilt condition in cotton yield
Materials and Methods
Geographically, Sardarkrushinagar campus of
Sardarkrushinagar Dantiwada Agricultural
University, where the experiment was laid out
is situated at 24 -19’ North latitude and 72o –
10' East longitude with an altitude of 154.52
metre from the mean sea level It represents the North Gujarat Agro-climatic Zone The soil of the experimental field was loamy sand
in texture, low in organic carbon (0.16) and available nitrogen (144), medium in available phosphorus (31) and high in available potash (283) Electrical conductivity was very low showing that the soil was free from salinity hazard (Table 1)
The experiments were carried out in FRBD (Factorial Randomized Block Design)design with three replications having the spacing 120
x 45cm Treatment divided into two factor, 1) Factor A: Chemicals (C), 2) Factor B: Varieties (V): a) Bt Cotton – Hybrid 6b) Non
Bt Cotton – G Cot Hybrid 12
Hand-thinned to 5 to 6 plants per meter row when the seedlings had approximately three true leaves The recommended dose of fertilizer to cotton is 160: 00: 00 N, P2O5 and K2O kg/ha Among this 80 kg N was applied
at the time of sowing as basal dose A top dressing of 40 kg N each was applied at 30 DAS and 60 DAS
Total eighteen treatment combinations were used The details of treatments are as under Three replications are utilized for recording observation for nondestructive analysis Five plant in each plots were randomly selected from net rows, tagged and were used to determine Plant height (cm), Days to flower initiation, Total no of flowers opened per plant, Total no of flowers abscission per plant and no of bud abscission per plant For destructive analysis plant sample were taken from three replications
Five plants were randomly selected for this purpose in net plots and carefully uprooted with the help of shevel from a depth of 60 cm
to determine Total dry weight of plant (g plant-1), Leaf area per plant (dm2 plant-1),
Trang 3Leaf area index and Chlorophyll content (mg
g-1 fresh weight) At the time of harvesting
the tagged five plants utilized for observations
recording and plants were harvested
separately for recording Seed cotton yield
(kg/ha), Biological yield (gm), Harvest index
(%), NAR (Net assimilative rate) (g-1 dm-2
day-1) and RGR (Relative growth rate) (g g-1
day-1) From each plot, plants were selected
randomly, for recording physiological
character Total dry weight of plant (g plant-1),
Leaf area per plant (dm2 plant-1), Leaf area
index, Chlorophyll content (mg g-1 fresh
weight), Seed cotton yield (kg/ha), Biological
yield (gm), Harvest index (%), NAR (Net
assimilative rate) (g-1 dm-2 day-1) and RGR
(Relative growth rate) (g g-1 day-1)
The data collected for all the characters were
subjected to statistical analysis by adopting
‘Analysis of Variance’ techniques as
described by Panse and Sukhatme (1978)
Results and Discussion
Interaction effect of different plant growth
regulators on Bt cotton and local hybrid
cotton plant height at 90 DAS
The effect of different plant growth regulators
on Bt cotton and local hybrid cotton at 90
DAS was found to be significant Application
of NAA 30 ppm at 80 DAS to Bt cotton
recorded significantly higher plant height
(95.33 cm) However, it was at par with GA3
50 ppm at 80 DAS (93.00 cm), NAA 30 ppm
at 60 DAS (92.00 cm) and GA3 50 ppm at 60
DAS (89.67 cm)
The lower plant height was recorded with MC
(84.33 cm) while in local hybrid cotton NAA
30 ppm at 60 DAS recorded significantly
higher plant height (92.08 cm) compared to
other treatments However, it was at par with
GA3 50 ppm at 60 DAS (92.00 cm), NAA 30
ppm at 80 DAS (91.92 cm), GA3 50 ppm at
80 DAS (90.50 cm), Urea 2 % at 80 DAS (88.00 cm) and Urea 2 % at 60 DAS (84.00 cm) (Table 3.1)
Interaction effect of different plant growth regulators on Bt cotton and local hybrid cotton for bud abscission at 90 DAS
The effect of different plant growth regulators
on Bt cotton and local hybrid cotton at 90 DAS was found to be significant In Bt cotton the number of bud abscission differed significantly among the treatments Number
of bud abscission was significantly less when application of NAA 30 ppm at 80 DAS (4.83) However, it was at par with MC 200 ppm at 60 DAS (6.00), MC 200 ppm at 80 DAS (6.50), Urea 2 % at 60 DAS (6.17) and Urea 2 % at 80 DAS (5.83) Significantly highest number of bud abscission was recorded in control (8.17) while in local hybrid cotton number of bud abscission was significantly less in NAA 30 ppm at 80 DAS (5.50) However, it was at par with MC 200 ppm at 60 DAS (7.00), MC 200 ppm at 80 DAS (6.33), Urea 2 % at 60 DAS (6.33) Significantly highest number of bud abscission was recorded in control (7.50) (Table 3.2)
Interaction effect of different plant growth regulators on Bt cotton and local hybrid cotton for flower abscission at 90 DAS
The effect of different plant growth regulators
on Bt cotton and local hybrid cotton at 90 DAS was found to be significant In Bt cotton the number of flower abscission differed significantly among the treatments Number of flower abscission was significantly less when NAA 30 ppm was applied at 80 DAS (7.83) However, it was at par with NAA 30 ppm at 60 DAS (8.83), GA3
50 ppm at 60 DAS (10.83), GA3 50 ppm at 80 DAS (9.50), MC 200 ppm at 60 DAS (13.00),
MC 200 ppm at 80 DAS (12.17), Urea 2 % at
Trang 460 DAS (11.17), Urea 2 % at 80 DAS (11.17)
Significantly highest number of flower
abscission was recorded in control (13.83)
while in local hybrid cotton number of flower
abscission was significantly less when NAA
30 ppm was applied at 60 DAS (9.17)
However, it was at par with GA350 ppm at 60
DAS (10.67), MC 200 ppm at 60 DAS
(13.50), MC 200 ppm at 80 DAS (12.33),
Urea 2 % at 60 DAS (11.33) and Urea 2 % at
80 DAS (11.00) Significantly highest number
of flower abscission was recorded in control
(14.50) (Table 3.3)
Interaction effect of different plant growth
regulators on Bt cotton and local hybrid
cotton for flowers opened at 90 DAS
The effect of different plant growth regulators
on Bt cotton and local hybrid cotton on
number of flower opened at 90 DAS was
found to be significant The significant effect
on flower opening was found due to plant
growth regulators applied to Bt cotton
Highest numbers of flowers were opened
when NAA 30 ppm applied at 80 DAS
(26.17).Significantly less number of flower
openings was recorded in MC 200 ppm at 80
DAS (19.50) while in local hybrid cotton
number of flower openings was significantly
higher in NAA 30 ppm at 60 DAS (24.17)
However, it was at par with NAA30 ppm at
80 DAS (22.67) and GA3 (50 ppm at 80 DAS
(22.50) Significantly less number of flower
openings was recorded in Control (17.33)
(Table 3.4)
Interaction effect of different plant growth
regulators on Bt cotton and local hybrid
cotton relative growth rate (RGR) at 60-90
DAS
The effect of different plant growth regulators
on Bt cotton and local hybrid cotton on
relative growth rate was found to be
significant In Bt cotton the higher RGR was
recorded when NAA 30 ppm sprayed at 80 DAS (0.0486) However, it was at par with NAA (30 ppm at 60 DAS) (0.0482) Significantly lower RGR was recorded in control (0.0430) In local hybrid cotton the higher RGR was recorded with NAA 30 ppm
at 80 DAS (0.0476) However, it was at par with NAA 30 ppm at 60 DAS (0.0475) and
GA3 50 ppm at 60 DAS (0.0471) Significantly lower RGR was recorded in control (0.0417) (Table 3.5)
Interaction effect of different plant growth regulators on Bt cotton and local hybrid cotton net assimilation rate (NAR) at 60-90 DAS
The effect of different plant growth regulators
on Bt cotton and local hybrid cotton on net assimilation rate was found to be significant
In Bt cotton the higher NAR was recorded when NAA 30 ppm was sprayed at 80 DAS (0.124) However, it was at par with NAA 30 ppm at 60 DAS (0.122), GA350 ppm at 60 DAS (0.122), GA3 50 ppm at 80 DAS (0.123), Urea 2 % at 60 DAS (0.121) and Urea 2 % at 80 DAS (0.122) Significantly lower NAR was recorded in control (0.112)
In case of local hybrid cotton the higher NAR was recorded in NAA 30 ppm at 80 DAS (0.120) However, it was at par with NAA 30 ppm at 60 DAS (0.118), GA3 50 ppm at 60 DAS (0.118), GA3 50 ppm at 80 DAS (0.119), MC 200 ppm at 80 DAS (0.117) and Urea 2 % at 80 DAS (0.118) Significantly lower NAR was recorded in control (0.104) (Table 3.6)
Interaction effect of different plant growth regulators on Bt cotton and local hybrid cotton leaf area index (LAI) at 90 DAS
The effect of different plant growth regulators
on Bt cotton and local hybrid cotton on leaf area index was found to be significant In Bt cotton the higher leaf area index was recorded
Trang 5with NAA 30 ppm at 80 DAS (1.85)
Significantly lower leaf area index was
recorded in MC 200 ppm at 60 DAS (1.18) In
local hybrid cotton the higher leaf area index
was recorded with MC 200 ppm at 60 DAS
(1.55) However, it was at par with NAA 30
ppm at 60 DAS (1.51), NAA 30 ppm at 80
DAS (1.34), GA3 50 ppm at 60 DAS (1.47),
GA3 50 ppm at 80 DAS (1.41), Urea 2 % at
60 DAS (1.38), Urea 2 % at 80 DAS (1.41)
(Table 3.7)
Interaction effect of different plant growth
regulators on Bt cotton and local hybrid
cotton chlorophyll content at 90 DAS
The effect of different plant growth regulators
on Bt cotton and local hybrid cotton on
chlorophyll content was found to be
significant In Bt cotton the higher
chlorophyll content was recorded with MC
200 ppm applied at 80 DAS (1.56)
Significantly lower chlorophyll content was
recorded with control (1.30) In local hybrid
cotton the higher chlorophyll content was
recorded with MC 200 ppm at 80 DAS (1.44)
However, it was at par with MC 200 ppm at
60 DAS (1.42), GA3 50 ppm at 60 DAS
(1.37), GA3 50 ppm at 80 DAS (1.38),
NAA30 ppm at 60 DAS (1.34), NAA30 ppm
at 80 DAS (1.35), Urea 2 % at 60 DAS (1.34) and Urea 2 % at 80 DAS (1.35) Significantly lower chlorophyll content was recorded in control (1.09) (Table 3.8)
Interaction effect of different plant growth regulators on Bt cotton and local hybrid cotton on seed cotton yield per plant (g
The effect of different plant growth regulators
on Bt cotton and local hybrid cotton on seed cotton yield per plant was found to be significant In Bt cotton the higher seed cotton yield per plant was recorded with the spraying of NAA 30 ppm at 80 DAS (70.03)
However, it was at par with NAA 30 ppm at
60 DAS (66.50), GA3 50 ppm at 60 DAS (67.65) and GA3 50 ppm at 80 DAS (68.05) Significantly lower seed cotton yield per plant was recorded in Control (51.70) In local hybrid cotton the higher seed cotton yield per plant was recorded with the application of NAA 30 ppm at 80 DAS (61.00) However, it was at par with NAA 30 ppm at 60 DAS (60.33) and GA3 50 ppm at 80 DAS (Table 3.9)
Table.1 Physico-chemical properties of soil of experimental field
Sr
No
(a) Sand (%) 84.90 84.98 International Pipette Method
(Piper, 1966)
(d) Soil texture Loamy sand
(a) Soil pH (1:2.5, Soil:
Water Ratio)
7.6 7.4 Potentiometric method (Jackson, 1978) (b) EC (dSm-1 at 25oC) 0.13 0.18 Schofield method (Jackson, 1978)
(c) Organic carbon (%) 0.17 0.15 Weakley and Black’s rapid titration method
(Jackson, 1978) (d) Available N (kg ha-1) 149 138 Alkaline Permanganate method (Jackson, 1978) (e) Available P 2 O 5 (kg ha-1) 29.24 32.93 Olsen’s Method (Jackson, 1978)
(f) Available K 2 O (kg ha-1) 287 279 Flame photometer method (Jackson, 1978)
Trang 6Table.2 Treatment combinations
chloride)
chloride)
chloride)
chloride)
Table.3.1 Interaction effect of plant growth
regulators on plant height (cm) at 90 DAS
Table.3.2 Interaction effect of plant growth
regulators on number of bud abscission at 90 DAS
90 DAS
Bt Non Bt
T1- NAA 30 ppm 60DAS 92.00 92.08
T2--NAA 30 ppm 80 DAS 95.33 91.92
T3- GA3 50 ppm 60 DAS 89.67 92.00
T4- GA3 50 ppm 80 DAS 93.00 90.50
T5- MC 200 ppm 60 DAS 84.33 81.00
T6- MC 200 ppm 80 DAS 85.25 82.73
T7- Urea 2 % 60 DAS 85.67 84.00
T8- Urea 2 % 80 DAS 86.00 88.00
T9- Control (No Spray) 85.33 66.67
90 DAS
Bt Non Bt
T1- NAA 30 ppm 60DAS 5.17 6.00
T2--NAA 30 ppm 80 DAS 4.83 5.50
T3- GA3 50 ppm 60 DAS 5.50 6.17
T4- GA3 50 ppm 80 DAS 5.50 5.83
T5- MC 200 ppm 60 DAS 6.00 7.00
T6- MC 200 ppm 80 DAS 6.50 6.33
T7- Urea 2 % 60 DAS 6.17 6.33
T8- Urea 2 % 80 DAS 5.83 6.17
T9- Control (No Spray) 8.17 7.50
Trang 7Table.3.3 Interaction effect of plant growth
regulators on number of flowers abscission at
90 DAS
Table.3.4 Interaction effect of plant growth
regulators on number of flowers opened at 90 DAS
90 DAS
Bt Non Bt
T1- NAA 30 ppm 60DAS 8.83 9.17
T2--NAA 30 ppm 80 DAS 7.83 10.00
T3- GA3 50 ppm 60 DAS 10.83 10.67
T4- GA3 50 ppm 80 DAS 9.50 9.17
T5- MC 200 ppm 60 DAS 13.00 13.50
T6- MC 200 ppm 80 DAS 12.17 12.33
T7- Urea 2 % 60 DAS 11.17 11.33
T8- Urea 2 % 80 DAS 11.17 11.00
T9- Control (No Spray) 13.83 14.50
90 DAS
Bt Non Bt
T1- NAA 30 ppm 60DAS 23.50 24.17
T2--NAA 30 ppm 80 DAS 26.17 22.67
T3- GA3 50 ppm 60 DAS 23.33 20.67
T4- GA3 50 ppm 80 DAS 23.17 22.50
T5- MC 200 ppm 60 DAS 20.83 19.00
T6- MC 200 ppm 80 DAS 19.50 20.83
T7- Urea 2 % 60 DAS 20.17 20.50
T8- Urea 2 % 80 DAS 21.00 20.83
T9- Control (No Spray) 20.67 17.33
Table.3.5 Interaction effect of plant growth
at 90 DAS
Table.3.6 Interaction effect of plant growth
60 – 90 DAS
Bt Non Bt
T 1 - NAA 30 ppm 60DAS 0.0482 0.0475
T 2- -NAA 30 ppm 80 DAS 0.0486 0.0476
T 3 - GA 3 50 ppm 60 DAS 0.0471 0.0471
T 4 - GA 3 50 ppm 80 DAS 0.0473 0.0464
T 5 - MC 200 ppm 60 DAS 0.0433 0.0431
T 6 - MC 200 ppm 80 DAS 0.0435 0.0432
T 7 - Urea 2 % 60 DAS 0.0450 0.0445
T 8 - Urea 2 % 80 DAS 0.0453 0.0451
T 9 - Control (No Spray) 0.0430 0.0417
60 – 90 DAS
Bt Non Bt
T 1 - NAA 30 ppm 60DAS 0.122 0.118
T 2- -NAA 30 ppm 80 DAS 0.124 0.120
T 3 - GA 3 50 ppm 60 DAS 0.122 0.118
T 4 - GA 3 50 ppm 80 DAS 0.123 0.119
T 5 - MC 200 ppm 60 DAS 0.118 0.115
T 6 - MC 200 ppm 80 DAS 0.119 0.117
T 7 - Urea 2 % 60 DAS 0.121 0.115
T 8 - Urea 2 % 80 DAS 0.122 0.118
T 9 - Control (No Spray) 0.112 0.104